Files
CodeNavigator/web/city.js
T
Andy Dixon c31b0b3d39 Add blade signs so names read while walking along walls
Flat wall signs vanish at grazing angles. Walls facing a walker now
also carry blade signs projecting perpendicular to the wall, repeated
along long walls and offset from the flat signs. Each blade is two
back-to-back faces; the sign shader discards whichever face would read
mirrored from the viewer's side. Blades shorten to the free space in
front of the wall and are skipped when a neighbouring building is
closer than 1.2 m of sign.
2026-06-07 11:51:13 +01:00

340 lines
17 KiB
JavaScript

// Code as a city: folders become districts and blocks separated by roads, files become buildings.
// Everything here is plain data and maths in metres, so it can be tested without a browser.
// Squarified treemap: calls output(entry, x, y, w, h, depth) for each entry, largest first.
export function squarifiedLayout(entries, x, y, w, h, depth, output) {
if (!entries.length || w <= 0 || h <= 0) return;
const total = entries.reduce((sum, entry) => sum + Math.max(.0001, entry.weight), 0), scale = w * h / total;
const remaining = entries.map(entry => ({ entry, area: Math.max(.0001, entry.weight) * scale }));
const worst = (row, side) => {
if (!row.length) return Infinity;
let sum = 0, largest = 0, smallest = Infinity;
for (const item of row) { sum += item.area; largest = Math.max(largest, item.area); smallest = Math.min(smallest, item.area); }
return Math.max(side * side * largest / (sum * sum), (sum * sum) / (side * side * smallest));
};
const place = row => {
const area = row.reduce((value, item) => value + item.area, 0);
if (w >= h) {
const rowWidth = Math.min(w, area / Math.max(.0001, h)); let rowY = y;
for (const item of row) { const itemHeight = item.area / Math.max(.0001, rowWidth); output(item.entry, x, rowY, rowWidth, itemHeight, depth); rowY += itemHeight; }
x += rowWidth; w = Math.max(0, w - rowWidth);
} else {
const rowHeight = Math.min(h, area / Math.max(.0001, w)); let rowX = x;
for (const item of row) { const itemWidth = item.area / Math.max(.0001, rowHeight); output(item.entry, rowX, y, itemWidth, rowHeight, depth); rowX += itemWidth; }
y += rowHeight; h = Math.max(0, h - rowHeight);
}
};
let row = [];
while (remaining.length) {
const next = remaining[0], side = Math.max(.0001, Math.min(w, h));
if (!row.length || worst([...row, next], side) <= worst(row, side)) row.push(remaining.shift());
else { place(row); row = []; }
}
if (row.length) place(row);
}
export const CITY = {
squareMetresPerLine: 1.1, // building footprint per source line
minLines: 40, // small files still get a walkable kiosk
roadWidths: [18, 12, 8, 6], // avenues between districts, then narrower streets per folder depth
sidewalk: 2.5, // kerb inside each block before buildings start
setback: 1.2, // gap between neighbouring buildings
cellSize: 32, // spatial grid cell for collision and picking
};
// Storeys scale with complexity: a flat data file is a low warehouse, dense logic is a tower.
export function buildingHeight(file) {
return 6 + 10 * Math.log2(1 + Math.max(0, file.complexity || 0));
}
function buildTree(files, name) {
const root = { name, path: '', children: new Map(), files: [], weight: 0 };
for (const file of files) {
const parts = file.path.split('/'); parts.pop(); let node = root;
for (const part of parts) {
if (!node.children.has(part)) node.children.set(part, { name: part, path: node.path ? `${node.path}/${part}` : part, children: new Map(), files: [], weight: 0 });
node = node.children.get(part);
}
node.files.push(file);
}
const weigh = node => {
node.weight = node.files.reduce((sum, file) => sum + Math.max(CITY.minLines, file.lines || 0), 0);
for (const child of node.children.values()) node.weight += weigh(child);
return node.weight;
};
weigh(root);
return root;
}
// Returns { width, height, buildings: Map(fileId -> {x,y,w,h,height}), blocks: [{node,depth,x,y,w,h}] }.
export function layoutCity(files, name = '') {
const root = buildTree(files, name);
const area = root.weight * CITY.squareMetresPerLine * 1.9; // roads, sidewalks and setbacks
const width = Math.sqrt(area * 1000 / 680), height = area / width;
const buildings = new Map(), blocks = [];
const visit = (node, x, y, w, h, depth) => {
if (depth > 0) {
// Half a road on every side, so neighbouring blocks are a full road apart.
const half = Math.min(CITY.roadWidths[Math.min(depth - 1, CITY.roadWidths.length - 1)] / 2, w * .2, h * .2);
x += half; y += half; w -= half * 2; h -= half * 2;
}
blocks.push({ node, depth, x, y, w, h });
const kerb = Math.min(CITY.sidewalk, w * .15, h * .15);
const values = [...node.children.values(), ...node.files.map(file => ({ file, weight: Math.max(CITY.minLines, file.lines || 0) }))];
const total = values.reduce((sum, value) => sum + value.weight, 0), floor = total / Math.max(1, values.length * 8);
const entries = values.map(value => ({ value, weight: Math.max(value.weight, floor) })).sort((a, b) => b.weight - a.weight);
squarifiedLayout(entries, x + kerb, y + kerb, w - kerb * 2, h - kerb * 2, depth, (entry, rx, ry, rw, rh) => {
const value = entry.value;
if (!value.file) return visit(value, rx, ry, rw, rh, depth + 1);
const gap = Math.min(CITY.setback / 2, rw * .12, rh * .12);
buildings.set(value.file.id, { x: rx + gap, y: ry + gap, w: rw - gap * 2, h: rh - gap * 2, height: buildingHeight(value.file) });
});
};
visit(root, 0, 0, width, height, 0);
return { width, height, buildings, blocks };
}
// Uniform grid over building footprints, for collision and picking near a point or along a ray.
export function spatialIndex(entries, cellSize = CITY.cellSize) {
const cells = new Map();
for (const entry of entries) {
const x0 = Math.floor(entry.x / cellSize), x1 = Math.floor((entry.x + entry.w) / cellSize);
const y0 = Math.floor(entry.y / cellSize), y1 = Math.floor((entry.y + entry.h) / cellSize);
for (let cy = y0; cy <= y1; cy++) for (let cx = x0; cx <= x1; cx++) {
const key = cx * 65536 + cy, cell = cells.get(key);
if (cell) cell.push(entry); else cells.set(key, [entry]);
}
}
return {
cellSize,
near(x, y, radius) {
const found = new Set();
for (let cy = Math.floor((y - radius) / cellSize); cy <= Math.floor((y + radius) / cellSize); cy++)
for (let cx = Math.floor((x - radius) / cellSize); cx <= Math.floor((x + radius) / cellSize); cx++)
for (const entry of cells.get(cx * 65536 + cy) || []) found.add(entry);
return found;
},
};
}
// Distance along the ray to an axis-aligned box from z=0 to z=height, or Infinity.
export function rayBox([ox, oy, oz], [dx, dy, dz], box) {
let near = 0, far = Infinity;
for (const [o, d, min, max] of [[ox, dx, box.x, box.x + box.w], [oy, dy, box.y, box.y + box.h], [oz, dz, 0, box.height]]) {
if (Math.abs(d) < 1e-9) { if (o < min || o > max) return Infinity; continue; }
let t0 = (min - o) / d, t1 = (max - o) / d;
if (t0 > t1) [t0, t1] = [t1, t0];
near = Math.max(near, t0); far = Math.min(far, t1);
if (near > far) return Infinity;
}
return near;
}
// Nearest building hit by a ray: { entry, distance } or null.
// ponytail: tests every building; walk the spatial grid along the ray if repos pass ~100k files.
export function pickRay(origin, dir, entries, maxDistance = Infinity) {
let best = null, distance = maxDistance;
for (const entry of entries) {
const t = rayBox(origin, dir, entry);
if (t < distance) { distance = t; best = entry; }
}
return best && { entry: best, distance };
}
// Pushes a circle of `radius` at (x, y) out of every building it overlaps.
export function collide(x, y, radius, index) {
for (let pass = 0; pass < 3; pass++) {
let moved = false;
for (const b of index.near(x, y, radius + 1)) {
const nx = Math.max(b.x, Math.min(x, b.x + b.w)), ny = Math.max(b.y, Math.min(y, b.y + b.h));
let dx = x - nx, dy = y - ny;
const distance = Math.hypot(dx, dy);
if (distance >= radius) continue;
if (distance === 0) {
// Centre inside the footprint: leave through the nearest wall.
const exits = [[b.x - radius - x, 0], [b.x + b.w + radius - x, 0], [0, b.y - radius - y], [0, b.y + b.h + radius - y]];
[dx, dy] = exits.reduce((best, exit) => Math.hypot(...exit) < Math.hypot(...best) ? exit : best);
x += dx; y += dy;
} else {
x = nx + dx / distance * radius; y = ny + dy / distance * radius;
}
moved = true;
}
if (!moved) break;
}
return { x, y };
}
// Horizontal forward and right vectors for a heading; yaw 0 faces -y (north on the map).
export function heading(yaw) {
return { forward: [-Math.sin(yaw), -Math.cos(yaw)], right: [Math.cos(yaw), -Math.sin(yaw)] };
}
export const MOVE = { walk: 7, run: 18, fly: 40, flyFast: 160, radius: .45, eyeHeight: 1.7 };
// Advances a walk/fly camera by dt seconds. input: {forward, right, up} in -1..1 and run (bool).
export function stepCamera(camera, input, dt, index, bounds) {
// Sub-steps keep a long frame from carrying the walker through a thin building.
for (; dt > .05; dt -= .05) stepCamera(camera, input, .05, index, bounds);
const fly = camera.view === 'fly', speed = (fly ? (input.run ? MOVE.flyFast : MOVE.fly) : (input.run ? MOVE.run : MOVE.walk)) * dt;
const { forward, right } = heading(camera.lookYaw);
let mx = forward[0] * input.forward + right[0] * input.right, my = forward[1] * input.forward + right[1] * input.right;
const length = Math.hypot(mx, my);
if (length > 1) { mx /= length; my /= length; }
let x = camera.ex + mx * speed, y = camera.ey + my * speed;
if (fly) {
// Flying follows the view pitch, so looking down and pressing forward descends.
const vertical = Math.sin(camera.lookPitch) * input.forward + input.up;
camera.ez = Math.max(MOVE.eyeHeight, Math.min(3000, camera.ez + vertical * speed));
} else {
camera.ez = MOVE.eyeHeight;
}
if (camera.ez < 400) ({ x, y } = collide(x, y, MOVE.radius, { near: (px, py, r) => [...index.near(px, py, r)].filter(b => b.height + .5 > camera.ez - MOVE.eyeHeight) }));
camera.ex = Math.max(-150, Math.min(bounds.width + 150, x));
camera.ey = Math.max(-150, Math.min(bounds.height + 150, y));
return camera;
}
// Deepest folder block containing a point, for the "you are here" address.
export function blockAt(blocks, x, y) {
let best = null;
for (const block of blocks) if (block.depth > 0 && x >= block.x && x <= block.x + block.w && y >= block.y && y <= block.y + block.h && (!best || block.depth > best.depth)) best = block;
return best;
}
// Where a ray meets the ground plane (z = 0), or null if it points up.
export function groundHit([ox, oy, oz], [dx, dy, dz]) {
if (dz >= -1e-6) return null;
const t = -oz / dz;
return [ox + dx * t, oy + dy * t];
}
// ---- Sign placement. A quad is { c: centre, u: half-width axis, v: half-height axis } in metres. ----
// Text lying flat, reading left to right along +x with its top toward north (-y).
export function flatQuad(cx, cy, z, width, height) {
return { c: [cx, cy, z], u: [width / 2, 0, 0], v: [0, -height / 2, 0] };
}
// The four walls of a footprint: centre on the ground, outward normal, width.
function walls(b) {
return [
{ c: [b.x + b.w / 2, b.y + b.h], n: [0, 1], width: b.w },
{ c: [b.x + b.w / 2, b.y], n: [0, -1], width: b.w },
{ c: [b.x + b.w, b.y + b.h / 2], n: [1, 0], width: b.h },
{ c: [b.x, b.y + b.h / 2], n: [-1, 0], width: b.h },
];
}
// Vertical quad just outside a wall, reading left to right for someone facing that wall.
function wallQuad(wall, z, width, height) {
const offset = .06, right = [wall.n[1], -wall.n[0]];
return { c: [wall.c[0] + wall.n[0] * offset, wall.c[1] + wall.n[1] * offset, z], u: [right[0] * width / 2, right[1] * width / 2, 0], v: [0, 0, height / 2] };
}
// Name signs at first-floor height on the walls that face the viewer.
export function wallSigns(b, eye, aspect, height = .9, z = 3.2) {
const out = [];
for (const wall of walls(b)) {
if ((eye[0] - wall.c[0]) * wall.n[0] + (eye[1] - wall.c[1]) * wall.n[1] <= 0) continue;
// Long walls repeat the sign every ~24 m so one is always near someone walking past.
const count = Math.max(1, Math.floor(wall.width / 24)), segment = wall.width / count, along = [wall.n[1], -wall.n[0]];
const width = Math.min(segment * .85, aspect * height);
for (let i = 0; i < count; i++) {
const offset = (i + .5) * segment - wall.width / 2;
out.push(wallQuad({ ...wall, c: [wall.c[0] + along[0] * offset, wall.c[1] + along[1] * offset] }, Math.min(z, b.height * .5), width, width / aspect));
}
}
return out;
}
// The wall most squarely facing the viewer, covered with the file's source at the texture's aspect.
export function facadeQuad(b, eye, aspect) {
let best = null, score = 0;
for (const wall of walls(b)) {
const dx = eye[0] - wall.c[0], dy = eye[1] - wall.c[1], facing = (dx * wall.n[0] + dy * wall.n[1]) / (Math.hypot(dx, dy) || 1);
if (facing > score) { score = facing; best = wall; }
}
if (!best) return null;
let width = best.width * .9, height = width / aspect;
const room = Math.max(1, (b.height - 1.5) * .92);
if (height > room) { height = room; width = height * aspect; }
return wallQuad(best, 1.2 + height / 2, width, height);
}
// ---- Guided tour, shareable places and touch input ----
// Largest districts first, each with a helicopter pose that frames it.
export function tourStops(districts, limit = 6) {
return [...districts].sort((a, b) => b.lines - a.lines).slice(0, limit).map((district, index) => {
const b = district.block;
return { district, pose: { x: b.x + b.w / 2, y: b.y + b.h / 2, distance: Math.max(120, Math.max(b.w, b.h) * 1.35), pitch: .5, yaw: -.6 + index * 1.1 } };
});
}
const CAMERA_FIELDS = { heli: ['x', 'y', 'yaw', 'pitch', 'distance'], walk: ['ex', 'ey', 'ez', 'lookYaw', 'lookPitch'], fly: ['ex', 'ey', 'ez', 'lookYaw', 'lookPitch'] };
const GITHUB_REPO = /^https:\/\/github\.com\/[\w.-]+\/[\w.-]+$/;
// A place in a codebase as a URL fragment: repository, view, city camera and selected file.
export function encodePlace({ repo, view, camera, file }) {
const params = new URLSearchParams({ repo, view });
if (view === 'city' && camera && CAMERA_FIELDS[camera.view]) {
params.set('cam', `${camera.view}:${CAMERA_FIELDS[camera.view].map(key => +camera[key].toFixed(key.startsWith('e') || key === 'x' || key === 'y' || key === 'distance' ? 1 : 3)).join(',')}`);
}
if (file) params.set('file', file);
return `#${params}`;
}
export function decodePlace(hash) {
const params = new URLSearchParams(String(hash || '').replace(/^#/, ''));
const repo = params.get('repo');
if (!repo || !GITHUB_REPO.test(repo)) return null;
const view = ['2d', '3d', 'city'].includes(params.get('view')) ? params.get('view') : '2d';
const place = { repo, view, file: params.get('file') || null, camera: null };
const [camView, values] = (params.get('cam') || '').split(':');
const numbers = (values || '').split(',').map(Number);
if (CAMERA_FIELDS[camView] && numbers.length === CAMERA_FIELDS[camView].length && numbers.every(Number.isFinite)) {
place.camera = { view: camView, ...Object.fromEntries(CAMERA_FIELDS[camView].map((key, i) => [key, numbers[i]])) };
}
return place;
}
// Virtual joystick: drag offset in pixels to forward/right in -1..1, with a small dead zone.
export function joystick(dx, dy, radius = 56) {
const length = Math.hypot(dx, dy);
if (length < radius * .12) return { forward: 0, right: 0 };
const scale = Math.min(1, length / radius) / length;
return { forward: -dy * scale, right: dx * scale };
}
// A quad's text reads correctly only from the side where (u x v) points away from the viewer
// (the world is left-handed). The sign shader applies the same test to skip mirrored faces.
export function readableFrom(quad, eye) {
const [ux, uy, uz] = quad.u, [vx, vy, vz] = quad.v;
const n = [uy * vz - uz * vy, uz * vx - ux * vz, ux * vy - uy * vx];
return n[0] * (eye[0] - quad.c[0]) + n[1] * (eye[1] - quad.c[1]) + n[2] * (eye[2] - quad.c[2]) < 0;
}
// Blade signs stick out from the wall like shop signs, so names read while walking alongside.
// Each blade is two back-to-back faces; only the one readable from the viewer's side is drawn.
// clearance(x, y, direction) returns the free distance outward, so blades never pierce a neighbour.
export function bladeSigns(b, eye, aspect, clearance, height = .7, z = 4.2) {
const out = [], inset = .15;
for (const wall of walls(b)) {
if ((eye[0] - wall.c[0]) * wall.n[0] + (eye[1] - wall.c[1]) * wall.n[1] <= 0) continue;
const count = Math.max(1, Math.floor(wall.width / 24)), segment = wall.width / count, along = [wall.n[1], -wall.n[0]];
const signZ = Math.max(2.6, Math.min(z, b.height - height));
for (let i = 0; i < count; i++) {
// Blades sit a third of the way into each segment so they don't overlap the flat wall sign.
const offset = (i + .3) * segment - wall.width / 2, x = wall.c[0] + along[0] * offset, y = wall.c[1] + along[1] * offset;
const room = clearance ? clearance(x, y, wall.n) - inset - .5 : Infinity;
const width = Math.min(3.2, aspect * height, room);
if (width < 1.2) continue;
const c = [x + wall.n[0] * (inset + width / 2), y + wall.n[1] * (inset + width / 2), signZ];
const u = [wall.n[0] * width / 2, wall.n[1] * width / 2, 0], v = [0, 0, width / aspect / 2];
out.push({ c, u, v }, { c, u: u.map(value => -value), v });
}
}
return out;
}